shadertoy
Write, explain, debug, and port ShaderToy-style fragment shaders. Use when the user asks for ShaderToy code, wants help with `mainImage`, `fragCoord`, `iTime`, `iResolution`, `iMouse`, `iChannel0..3`, buffer passes, common fullscreen coordinate math, or needs to migrate a ShaderToy effect into raw WebGL, Three.js, React Three Fiber, or a browser canvas demo. NOT for general material shaders, vertex shaders, or non-ShaderToy rendering pipelines unless the task clearly starts from ShaderToy code o
